"The scene was quite chaotic," Lamoureux said. People were on the ground "screaming for help."

First, Lamoureux said, the officers tried dousing the dog with pepper spray. "That didn't help. They tried kicking the dog while it was biting someone; that didn't work. Then it turned for the officers, that's when they each shot one round," killing the dog, Lamoureux said.

The five, all adults, told police they had a gathering to celebrate the Fourth of July and the dog got agitated as several people started play-wrestling, so they put the dog in the house. The dog, Lamoureux said, apparently got out twice through a window, attacking the party-goers, each time acting more aggressively.

The dog's body was turned over to the state Department of Environmental Management for "disease testing," Lamoureux said, adding the department did not appear to have any previous complaints on the dog. The police are also looking into whether the dog was licensed and up-to-date on vaccines.